Tough day for Jason Day at the Dell Technologies Match Play.

AUSTIN, Texas — Defending champion Jason Day lasted only six holes at the Dell Technologies Match Play until a heavy heart forced an early departure.

Rory McIlroy and Jordan Spieth might not be far behind.

The opening round of golf’s most unpredictable tournament took an unusual turn Wednesday when the third-seeded Day abruptly conceded his match to Pat Perez, then wiped away tears as he revealed his mother has lung cancer. Day withdrew to be with her in Ohio for surgery on Friday.

Dustin Johnson had no trouble in his debut as the No. 1 seed. He had five birdies in his opening eight holes at Austin Country Club and there wasn’t much Webb Simpson could do but try to extend the match as long as he could. It lasted 15 holes in a 5-and-3 victory.

McIlroy, the 2015 champion and a semifinalist last year, appeared to seize control against Soren Kjeldsen when he won three consecutive holes to take the lead. Kjeldsen, crisp as ever with his short irons, ran off four consecutive birdies to end the match. Kjeldsen was 6 under on the round.

Spieth didn’t up put much of a fight against Hideto Tanihara of Japan, making his debut in Match Play.

With the Texas crowd on his side, Spieth missed a short birdie attempt that would have given him the lead on No. 5. Two holes later, Tanihara poured in an 18foot birdie putt. Spieth couldn’t match him and never caught up.

Spieth and McIlroy are not done yet, though they need some help.

The best record from the 16 four- man groups advance to the knockout stage on Saturday. Ties are determined by a sudden-death playoff, and head-tohead matchups do not count.

“I obviously have to take care of my end of the bargain tomorrow,” said Spieth, who next faces Yuta Ikeda.

Only nine of the 32 matches went the distance. Charl Schwartzel had the shortest day, ending his match against Byeong Hun on the 13th hole.